The Human Cytokine (dual-color cytokine) assay is a modification of the Enzyme-Linked ImmunoSPOT (ELISPOT) assay and is designed to detect double cytokine-secreting T cells at the single cell level. The assay is based on the use of fluorescent- instead of enzymatic-labeled conjugates. Previous attempts to develop an immunoenzymatic dual-color ELISPOT assay were less successful because of problematic interpretation of mixed color spots.
The dual-color assay, however, provides good discrimination between single and double cytokine-secreting cells and is particularly suited to detect T cell subpopulations with a characteristic cytokine profile. The sensitivity of the assay lends itself to measure very low frequencies of cytokine-secreting T cells.